Many solid crop protection agents are currently supplied in the form of wettable powders and granules. Typically, the herbicidal, fungicidal or insecticidal active ingredients are used together with inert fillers, such as chalk or kaolin, in particular surface active substances, in the preparation of such formulations so that the formulations are well wetted and dispersed in water. The inclusion of wetting agents lowers the surface tension of the spray mix. As a result, uniform wetting of the leaf surface is achieved. However, due to this lowered surface tension, these spray mixtures also tend to foam.
European patent application EP 0 561 265 suggests reduction of the tendency of foaming of such solid formulation by the addition of certain defoamer agents selected from the group of perfluoroalkylphosphinic acids and/or perfluoroalkylphosphonic acids and/or their salts. The formulations disclosed by this reference are prepared either by spray drying or fluidized bed granulation of aqueous suspensions containing the formulation ingredients. However, depending on the ingredients, the solid formulations obtained by spray drying or fluidized bed granulation exhibit higher tendency to develop dust when added to water in the spray tank. This results in end-users being exposed to higher dose rates of the active ingredient. The present invention provides solid formulations for crop protection with reduced tendency of foaming and dustiness.